Deferred items comprised €31 million (2016: €26 million) in prepaid expenses that will impact profit or loss in future periods.

With respect to trade accounts receivable that are neither impaired nor past due, there are no indications that the debtors will not meet their payment obligations. An aging overview of Trade receivables related to commercial transactions amounting to €1,356 million (2016: €1,343 million) is provided in the next table. The remaining balance reported as Trade receivables amounting to €172 million (2016: €146 million) is excluded from this analysis because it principally concerns reclaimable VAT and accruals that are not related to the payment behavior of customers.

Aging overview Trade receivables

in %

2017

2016

Neither past due nor impaired

80

82

1-29 days overdue

14

12

30-89 days overdue

5

3

90 days or more overdue

1

3

The changes in the allowance for doubtful accounts receivable are as follows: